Adjusting apparatus of gap width and method thereof

ABSTRACT

Provided is an adjusting method of a gap width of a laminated body composed of a color filter substrate and a TFT array substrate. A decompression chamber acting as a closed space communicating with a vacuum pump is decompressed, while a pressurization chamber that includes a decompression chamber is pressurized by driving a compressor.

BACKGROUND OF INVENTION

[0001] The present invention relates to a manufacturing method of adisplay device such as a liquid crystal display panel, more particularlyto an adjusting technique of a gap width between two device substrates.

[0002] As an image display device for a personal computer or othervarious monitors, a liquid crystal display device has been remarkablywidespread. Such a liquid crystal display device is generallyconstructed in such a manner that a backlight as a planar light sourcefor illumination is disposed on a back of a liquid crystal display panelto irradiate a liquid crystal surface of a specified expanse so as toeven the brightness thereon, and that an image formed on the liquidcrystal surface can be thereby visualized.

[0003] The liquid crystal display device includes a liquid crystaldisplay panel constructed by sealing a liquid crystal material betweentwo glass substrates, and a printed circuit board for driving the liquidcrystal material. The printed circuit board is mounted on the liquidcrystal display panel. A backlight unit is disposed on the back of theliquid crystal display panel with a liquid crystal display panel holdingframe being interposed therebetween. An outer frame surrounds theabove-described components. The glass substrate comprises the liquidcrystal display panel and the electrodes for driving the liquid crystalmaterial on which are formed.

[0004] A manufacturing process of a thin film transistor (TFT) liquidcrystal display device among such liquid crystal display devicesincludes the steps of having an array step, a cell step and a modulestep.

[0005] The array step includes installing TFTs, pixel electrodes, datalines, gate lines and the like on one of the two glass substrates. Sincethe TFTs are regularly arrayed on the glass substrate, the step isreferred to as an array step.

[0006] The cell step includes adhering the array substrate obtained inthe array step and a color filter substrate as a substrate opposite tothe array substrate, and injecting a liquid crystal material in a gap asa space between the two substrates, then sealing the gap. The substrateobtained in this step is referred to as a panel substrate.

[0007] The module step includes mounting an electric circuit forelectrically controlling the panel substrate obtained in the cell step,and further mounting parts such as a backlight and the like.

[0008] The contents of the cell step among the foregoing steps will bedescribed below.

[0009] Sealant is coated on the periphery of the color filter substrate.The sealant is provided for sealing the liquid crystal material betweenthe array substrate and the color filter substrate. Note that thesealant is coated in the form of a picture frame except a portionserving as an injection port for injecting the liquid crystal material.An example of such a sealant may include a thermosetting resin or anultraviolet-setting resin. Meanwhile, an orientation film is formed onthe array substrate, and then spacers are sprinkled thereon. The spacersare sprinkled for regulating a gap width between the array substrate andthe color filter substrate. Examples of such spacers may includespherical silica, spherical polyethylene or the like. Note that, insteadof sprinkling the spherical spacers, a technique of installing columnarspacers on the array substrate or the color filter substrate has beenexamined recently. After sprinkling the spacers, the color filtersubstrate is laminated onto the array substrate, and the sealant iscured. After curing the sealant, the liquid crystal material is injectedinto the gap between the array substrate and the color filter substrate.For the injection, an injection apparatus using an vacuum injectionmethod is used in many cases. Specifically, the laminated substrates aredisposed in a vacuum chamber, and the gap between the two substrates isevacuated. The foregoing injection port is immersed in the liquidcrystal material while maintaining the evacuated state, then, byreturning the chamber pressure from the vacuum to the atmosphericpressure, the liquid crystal material is filled in the gap. Thereafter,the injection port is sealed by the thermosetting resin or theultraviolet-setting resin. Thus summarizing the cell step.

[0010] The gap between the array substrate and the color filtersubstrate, that is, the cell gap, is extremely narrow. Typically the gapis 5 micrometers or less, desirably 3 to 5 micrometers. Image quality ofthe liquid crystal display device is greatly affected by the gap. Hence,the cell gap must be strictly controlled.

[0011] In order to control the cell gap, an even pressure must beapplied to the substrates when the color filter substrate is laminatedonto the array substrate. For this purpose, there have been variousproposals including the ones disclosed in the gazettes of JapanesePatent Laid-Open No. Sho 57 (1982)-188018, Japanese Patent PublicationNo. Hei 6 (1994)-16137 and Japanese Patent No. 2976925.

[0012] In the gazettes of Japanese Patent Laid-Open No. Sho 57(1982)-188018 and Japanese Patent Publication No. Hei 6 (1994)-16137,two methods have been proposed. In both of the methods, as shown inFIGS. 13 and 14, a laminated body composed of an array substrate 101 anda color substrate 102 whose gap has not been filled with the liquidcrystal material yet is disposed in a sealed container 100 formed of anelastic material, for example, silicon rubber. Thereafter, as shown inFIG. 13, the sealed container 100 is decompressed, and alternatively, asshown in FIG. 14, an air pressure is applied from the outside of thesealed container 100. Since each of these methods is a method ofapplying a pressure to the substrates by allowing a fluid pressure toact on the elastic material, the pressure applied to the substrates issufficiently even. Moreover, in the gazette of Japanese Patent No.2976925, a laminated body composed of an array substrate and a colorfilter substrate is disposed in a sealed container formed of an elasticmaterial. Then, the container is decompressed, and thereafter, suchdecompression is released to inject a liquid crystal material into acell gap by making use of a difference between pressures of the insideand outside of the container, which is generated when the container isreleased to the atmospheric pressure.

[0013] However, among the techniques disclosed in the gazettes ofJapanese Patent Laid-Open No. Sho 57 (1982)-188018, Japanese PatentPublication No. Hei 6 (1994)-16137 and Japanese Patent No. 2976925, inthe method of decompressing the sealed container, the difference betweenthe air pressures of the inside of the sealed container and the outsidethereof (atmosphere) cannot be set at 1 atm. or higher. Hence, only apressurization force up to 1 kgf/square cm can be applied to the arraysubstrate and the color filter substrate. Here, the sealant is coated tohave a thickness thicker than the cell gap, and the sprinkled spacersare overlapped from one to another. Thus, the cell gap with a desiredwidth is hard to obtain. Although described later in detail, with such apressurization force of about 1 kgf/square cm, the cell gap of a desiredwidth was not able to be obtained. Accordingly, by the conventionalmethod of decompressing the sealed container, it is difficult to adjustthe cell gap to a desired micro value. Meanwhile, in accordance with themethod of pressurizing the sealed container from the outside, it ispossible to apply a pressure higher than that by the method ofdecompressing the sealed container. However, when the sealed containeris released to the atmospheric pressure after the container ispressurized from the outside, a force acts in the direction where thearray substrate and the color filter substrate are torn off from eachother. Specifically, when a high air pressure is applied to the sealedcontainer from the outside, the air in the sealed container iscompressed so as to oppose such a pressurization force, resulting in apressure increase in the cell gap. When the sealed container is releasedto the atmospheric pressure from the pressure-increased state, thepressure in the cell gap exceeds the air pressure of the outside, thatis, 1 atm. in the atmosphere. Thus, the force acts in the directionwhere the array substrate and the color filter substrate are torn offfrom each other as described above, affecting adversely the control ofthe cell gap. Moreover, the force involves the possibility ofexfoliating the sealant and one of the array substrate and the colorfilter substrate from each other. Such exfoliation in an uncured stateof the sealant is not desirable since the exfoliation causes bubblemixing to the sealant and leads to the lowering of joining forces of thecured sealant.

SUMMARY OF INVENTION

[0014] The present invention was made with the foregoing circumstancesin mind. An object of the present invention is to provide an adjustingmethod of a gap width and an adjusting apparatus thereof, which areeffective when two sheets are laminated with a specified gap width.Another object of the present invention is to provide a manufacturingmethod of a display panel applying the adjusting method of the gap widthand the adjusting apparatus thereof.

[0015] Specifically, according to a first aspect of the presentinvention, provided is a method of adjusting a gap width of a laminatedbody composed of first and second substrates, having the steps ofobtaining the laminated body by laminating the first and secondsubstrates with a member for regulating the gap width interposedtherebetween, and decompressing the gap and applying a pressure to thelaminated body from the outside.

[0016] Moreover, according to a second aspect of the present invention,provided is an apparatus of adjusting a gap width of a laminated bodycomposed of first and second substrates and having a planar portion. Theapparatus includes a first chamber having a closed space foraccommodating the laminated body and provided with a flexible filmcontacting the planar portion of the laminated body, a second chamberhaving a closed space for accommodating the first chamber, adecompressor for applying a decompression force to the first chamber,and a pressurizer for applying a pressurization force to the secondchamber.

[0017] The present invention can be applied to the following method ofmanufacturing a display panel, in which the above-described method ofadjusting a gap width is applied to a method of manufacturing a displaydevice such as a liquid crystal display device. Specifically, accordingto a third aspect of the present invention, provided is a manufacturingmethod of a display panel in which a display medium is sealed between apair of substrates disposed opposite to each other, the substrates beingseparated from each other with a gap of a specified width, the methodcomprising the steps of: (a) coating sealant in the form of a pictureframe on a peripheral portion of at least one of the pair of substratesexcept an injection port for the display medium; (b) obtaining alaminated body having the gap of the specified width by laminating thepair of substrates with the sealant interposed therebetween; (c)applying a pressure to the pair of substrates from the outside whiledecompressing the gap; (d) curing the sealant; and (e) injecting thedisplay medium from the injection port after curing the sealant.

[0018] In the above, description has been made focusing on theapplication of the present invention to the adjustment of a gap.However, the present invention can be also recognized as a method and anapparatus of applying a pressure to an article. Specifically, accordingto a fourth aspect of the present invention, provided is a method ofapplying a pressure to an article with a hollow portion communicatingwith the outside. The method includes the steps of applying apressurization force to an article by a fluid in a state where thearticle is disposed in a closed space, allowing simultaneously a hollowportion to communicate with a system different from that of the closedspace, and applying a decompression force to the hollow portion throughthe different system.

[0019] Moreover, according to a fifth aspect of the present invention,provided is an apparatus for realizing the method of applying a pressureto an article. Specifically, the pressure applying apparatus of thisaspect is an apparatus of applying a pressure to an article having afirst chamber having a closed space for accommodating the article andprovided with a diaphragm in a part thereof, a second chamber providedwith a closed space including the first chamber, a decompressor forapplying a decompression force to the first chamber; and a pressurizerfor applying a fluid pressure to the second chamber. The apparatus ofapplying a pressure to an article is characterized in that the diaphragmapplies a pressure to the article when the decompressor applies thedecompression force to the first chamber, and applies the pressure tothe article when the pressurizer applies the fluid pressure to thesecond chamber.

[0020] Various other objects, features, and attendant advantages of thepresent invention will become more fully appreciated as the same becomesbetter understood when considered in conjunction with the accompanyingdrawings, in which like reference characters designate the same orsimilar parts throughout the several views.

BRIEF DESCRIPTION OF DRAWINGS

[0021] For a more complete understanding of the present invention andthe advantages thereof, reference is now made to the followingdescription taken in conjunction with the accompanying drawings.

[0022]FIG. 1 is an exploded perspective view of a liquid crystal displaydevice.

[0023]FIG. 2 is a flowchart schematically showing a manufacturingprocess of a liquid crystal display panel according to an embodiment ofthe present invention.

[0024]FIGS. 3A and 3B are views illustrating the manufacturing processof the liquid crystal display panel according to an embodiment of thepresent invention.

[0025]FIGS. 4A and 4B are views illustrating the manufacturing processof the liquid crystal display panel according to an embodiment of thepresent invention.

[0026]FIG. 5 is a side view showing a gap-width adjusting apparatus ofthe liquid crystal display panel according to an embodiment of thepresent invention.

[0027]FIG. 6 is an explanatory view showing a gap-adjusting step of theliquid crystal display panel according to an embodiment of the presentinvention.

[0028]FIG. 7 is an explanatory view showing a gap-adjusting process ofthe liquid crystal display panel according to an embodiment of thepresent invention.

[0029]FIG. 8 is an explanatory view showing the gap-adjusting process ofthe liquid crystal display panel according to an embodiment of thepresent invention.

[0030]FIG. 9 is an explanatory view showing the gap-adjusting process ofthe liquid crystal display panel according to an embodiment of thepresent invention.

[0031]FIG. 10 is an explanatory view showing the gap-adjusting processof the liquid crystal display panel according to an embodiment of thepresent invention.

[0032]FIG. 11 is a flowchart showing the gap-adjusting process of theliquid crystal display panel according to an embodiment of the presentinvention.

[0033]FIG. 12 is a view showing a heating furnace for curing sealant ofthe liquid crystal display panel according to an embodiment of thepresent invention.

[0034]FIG. 13 is a view showing one example of a conventionalgap-adjusting method of a liquid crystal display panel.

[0035]FIG. 14 is a view showing another example of the conventionalgap-adjusting method of the liquid crystal display panel.

DETAILED DESCRIPTION

[0036] As described above, in the conventional methods, a large pressurecan be applied to the substrates from the outside. However in this case,there occurs a phenomenon that the air compressed in the gap tears offthe array substrate and the color filter substrate after releasing thepressure applied thereto. This phenomenon occurs because the laminatedbody composed of the array substrate and the color filter substrate isdisposed in the sealed container. However, the inventor of the presentinvention has paid attention to the following. Specifically, the sealedcontainer is evacuated to be decompressed while a pressure is applied tothe substrates from the outside. Thus, a phenomenon that the pressurebetween the array substrate and the color filter substrate disposed inthe sealed container, that is, the pressure in the cell gap, gets higherthan the atmospheric pressure can be prevented.

[0037] In accordance with the method of adjusting a gap width of thefirst aspect, the gap is decompressed, and a pressure is applied to thelaminated body from the outside. Hence, the pressure in the gap can bemaintained at the atmospheric pressure or lower. Therefore, afterreleasing the decompression of the gap and the pressurization from theoutside, the occurrence of a force acting to tear off the first andsecond substrates from each other can be prevented.

[0038] Moreover, according to the method of adjusting a gap width of thefirst aspect, not only the gap is decompressed, but also a pressure isapplied to the laminated body from the outside. Therefore, apressurization force sufficient for obtaining a micro gap width can beobtained.

[0039] In this aspect, how much the gap is decompressed or how muchpressure is applied to the laminated body from the outside may beproperly determined depending on specifications such as a size of thelaminated body and a gap width thereof.

[0040] In this aspect of the method of adjusting a gap width, a methodof applying a pressure to the laminated body from the outside includes:a method of mounting a weight on the laminated body; and a method ofapplying a pressure thereto with a fluid taken as a pressure medium.However, the method with a fluid taken as a pressure medium isadvantageous in that a pressure to the laminated body can be made evenand that a step of applying a pressure to the laminated body is readilyincorporated into the manufacturing process of the laminated body.Hence, in the method of adjusting a gap width of this aspect, thepressure applied to the laminated body from the outside is desirablyapplied with a fluid taken as a pressure medium.

[0041] Moreover, in the method of adjusting a gap width of this aspect,a specific method of decompressing the gap includes: disposing thelaminated body in a first closed space and allowing a suction force toact in the first closed space. In this case, a specific method forapplying a pressure to the laminated body from the outside is asfollows. Specifically, a second closed space covering the first closedspace is formed, and a pressure can be applied to the laminated bodyfrom the outside by introducing a pressurized fluid into the secondclosed space.

[0042] The apparatus of adjusting a gap width of this aspect includes afirst chamber provided with a flexible film contacting the planarportion of the laminated body, and a decompressor for applying adecompression force to the first chamber. Hence, when the decompressionforce is applied to the first chamber by the decompressor, the gap inthe laminated body can be decompressed. In addition, a pressure can beapplied to the laminated body through the flexible film, which isinfluenced by the decompression force.

[0043] Moreover, in the apparatus of adjusting a gap width of thisaspect, the first chamber is accommodated in a second chamber. Hence, apressure can be applied to the laminated body accommodated in the firstchamber through the flexible film of the first chamber by supplying acompressed fluid from the pressurizer to the second chamber.

[0044] Here, in the apparatus of adjusting a gap width of this aspect,decompression of the gap of the laminated body and pressurization of thelaminated body from the outside can be simultaneously performed bysimultaneously decompressing the first chamber by the decompressor andpressurizing the second chamber by the pressurizer.

[0045] In the apparatus of adjusting a gap width of this aspect, thefirst chamber can be formed only of a flexible film, for example, abag-like container made of rubber.

[0046] However, it is desirable that the first chamber includes amounting stage for mounting the laminated body, and the flexible filmforming the closed space with the mounting stage by closely contacting aperiphery thereof to the mounting stage, and that the laminated body beaccommodated in the closed space. In the chamber formed as above, inwhich the flexible film is set so as to automatically ascend and descendrelative to the mounting stage, it is sufficient that the laminated bodyis only mounted on the mounting stage. Therefore, as compared with thecase of using the rubber-made container in which the laminated body isinserted, operability is improved.

[0047] Moreover, in the apparatus of adjusting a gap width of thisaspect, it is desirable that the pressurizer apply a pressurizationforce to the second chamber by introducing a pressurized fluid thereto,and the pressurization force be allowed to act on the laminated bodythrough the flexible film. This is because the pressurization force canbe evenly applied to the laminated body.

[0048] Since the method of manufacturing a display panel of this aspectincludes the step of applying a pressure to the pair of substrates fromthe outside while decompressing the gap, the gap of the display panelcan be adjusted to a desired micro value.

[0049] In accordance with steps of the present invention, the pressureapplied from the outside can be applied with a fluid taken as a pressuremedium. This is for controlling the gap width evenly by applying an evenpressure to the display panel to secure image quality.

[0050] In the method of manufacturing a display panel of this aspect,the curing process for the sealant can be performed while continuing thedecompression of the gap and the pressurization from the outside.However in this case, the decompression of the gap and thepressurization from the outside cannot be carried out during the curingprocess in the concerned apparatus, which is not desirable in terms ofproduction efficiency. Hence, it is desirable to perform the curingprocess of the sealant after releasing the decompression of the gap andthe pressurization from the outside. Particularly, in the method ofmanufacturing a display panel of this aspect, a pressure is applied tothe pair of substrates from the outside while the gap is decompressed.Accordingly, a force in a direction where the pair of substrates aretorn off does not act after releasing the decompression of the gap andthe pressurization from the outside. Therefore, the curing process forthe sealant can be performed after releasing the decompression of thegap and the pressurization from the outside. Here, in order not to allowthe force to act in the direction where the pair of substrates are tornoff after releasing the decompression of the gap and the pressurizationfrom the outside, the pressure in the gap must be set equal to theatmospheric pressure or lower by adjusting the decompression force tothe gap and the pressurization force applied from the outside.Hereinbelow, description will be made for an embodiment of the presentinvention with reference to the drawings.

[0051]FIG. 1 is an exploded perspective view showing a color thin filmtransistor (TFT) liquid crystal display device as one of applicationobjects of the present invention.

[0052] In FIG. 1, a metal-made shield 41 case forms an upper frame,which forms a display window 42 for defining an effective screen of aliquid crystal display module. A liquid crystal display panel 43, inwhich TFTs having source/drain electrodes, gate electrodes and amorphoussilicon layers and the like deposited thereon, color filters and thelike are laminated between a pair of glass substrates, and a liquidcrystal material is sealed therebetween.

[0053] On the liquid crystal display panel 43, a drain circuit substrate44, a gate circuit substrate 45 and an interface circuit substrate 46are formed. Furthermore, joiners 47, 48 and 49 are provided forconnecting the circuit substrates. These circuit substrates 44, 45 and46 are fixed to the shield case 41 with an insulating sheet 50interposed therebetween.

[0054] Meanwhile, under the liquid crystal display panel 43, a lightshielding spacer 61 is provided with a rubber cushion 60 interposedtherebetween, and further, a diffusion plate 62 and a prism sheet 63 areprovided thereunder. The diffusion plate 62 has a function of diffusinglight from a light guide plate 13 to be described later in order toobtain even planar light. The prism sheet 63 is used to increaseluminance in the front direction. Furthermore, under the prism sheet 63,the light guide plate 13 is provided, and a fluorescent lamp unit 65 isprovided on one side of the light guide plate 13. Two fluorescent lampunits 65 may be provided on two sides thereof. Still further, under thelight guide plate 13, a reflection plate 14 is provided. The reflectionplate 14 is constructed in such a manner that light made incident ontothe light guide plate 13 from the fluorescent lamp unit 65 can bereflected toward the direction of the liquid crystal display panel 43.Under the reflection plate 14, a lower case 67 with an aperture 68 isprovided.

[0055] In the pair of glass substrates comprising the liquid crystaldisplay panel 43, one constitutes the color filter substrate, and theother constitutes the TFT array substrate. As such glass substrates,non-alkali glass excellent in flatness with a thickness of, for example,0.7 mm is used.

[0056] The color filter substrate is made by sequentially laminating: onthe glass substrate, color filters composed of resin films containingdyes or pigments of three primary colors, that is, red (R), green (G)and blue (B); a black matrix as a light shielding film disposed amongpixels of the color filters; a protection film composed of a resin filmfor protecting the color filters and the black matrix; a commonelectrode composed of a transparent conductive thin film of indium tinoxide (ITO); and an orientation film composed of a polyimide thin filmfor orienting the liquid crystal material.

[0057] The TFT array substrate is made by forming: on the glasssubstrate, display electrodes as pixels for display composed of ITO;TFTs as switching elements for driving the liquid crystal; and storagecapacitors as signal retaining capacitors for operating the activematrix.

[0058] The color filter substrate and the TFT array substrate areadhered by the sealant as an adhesive in the peripheries thereof. Anarea surrounded by the sealant serves as an image display area.

[0059] In the image display area, the spacers are disposed forregulating the gap between the color filter substrate and the TFT arraysubstrate, that is, the thickness (cell gap) of the liquid crystallayer. For the spacers, silica (SiO2) or resin particles are used. Sincethe cell gap of the color TFT liquid crystal display device is about 5micrometers or less, desirably 3 to 5 micrometers, the spacers also witha diameter of about 5 micrometers or less, desirably 3 to 5 micrometersare used. Recently, columns capable of serving as spacers are alsoformed on the color filter substrate or the TFT array substrate by athin film forming process.

[0060] A description will now be made for a manufacturing process of theabove-described liquid crystal display panel 43 with reference to FIGS.2 to 4.

[0061] As shown in FIGS. 2 to 4, a color filter substrate 43 a and a TFTarray substrate 43 b are manufactured, respectively (S101 and S102 inFIG. 2).

[0062] Next, on the periphery of the color filter substrate 43 a,sealant Se is coated in the form of a picture frame (S103 in FIG. 2 andFIG. 3A). As the sealant Se, an ultraviolet-setting resin or athermosetting resin can be used as described above. In this embodiment,however, a thermosetting resin is used. The sealant Se is coated on theperiphery except an injection port for the liquid crystal material.

[0063] Meanwhile, on the TFT array substrate 43 b, spacers Sp aresprinkled by a dispenser (S104 in FIG. 2 and FIG. 3B).

[0064] After sprinkling the spacers Sp on the TFT array substrate 43 b,the color filter substrate 43 a is laminated on the TFT array substrate43 b to obtain a laminated body 43 c (S105 in FIG. 2, FIGS. 4A and 4B).

[0065] Features pertaining to the adjusting method of the cell gap ofthe laminated body 43 c, and the contents thereof will be describedlater in detail.

[0066] After adjusting the cell gap, a curing process for the sealant Seis carried out (S106 in FIG. 2). Since a thermosetting resin is used asthe sealant Se in this embodiment, the laminated body 43 c of the colorfilter substrate 43 a and the TFT array substrate 43 b is heated up to aspecified temperature (S107 in FIG. 2). FIG. 12 illustrates an exampleof a heating furnace 20. The heating furnace 20 is constituted of: afurnace body 21 having heaters 22 buried therein and a heating spaceprovided therein; and a rack 23 disposed in the heating space of thefurnace body 21. The rack 23 can hold a plurality of the laminatedbodies 43 c. The laminated bodies 43 c having been subjected to thecell-gap adjustment are sequentially placed in the rack 23, and when thespecified number of laminated bodies 43 c are placed therein, heating isstarted.

[0067] After the end of the curing process for the sealant Se, theliquid crystal material is injected. The injection of the liquid crystalmaterial is carried out by the vacuum injection method described above.Specifically, the laminated substrates are disposed in a vacuum chamber,and the gap between the two substrates is evacuated. Then, the foregoinginjection port is immersed in the liquid crystal material whilemaintaining the evacuated state, and thereafter, by returning thechamber pressure from the vacuum to the atmospheric pressure, the liquidcrystal material is filled in the gap. Thereafter, the injection port issealed by the thermosetting resin or the ultraviolet-setting resin (S108in FIG. 2).

[0068] A series of the steps for manufacturing the liquid crystaldisplay panel 43 has been described as above. Hereinbelow, descriptionwill be made for the adjusting method of a cell gap, which characterizesthis embodiment.

[0069]FIG. 5 is a view showing the construction of a cell-gap adjustingapparatus 1 for controlling the cell gap in this embodiment. Thecell-gap adjusting apparatus 1 comprises: a pressurization chamber 2; amounting stage 3 for mounting the laminated body 43 c of the colorfilter substrate 43 a and the TFT array substrate 43 b; and a frame 6capable of ascending and descending relative to the mounting stage 3.

[0070] To the pressurization chamber 2, a compressor 10 is connectedthrough a pressurization pipe 9 penetrating the pressurization chamber2. The pressurization chamber 2 is pressurized by driving the compressor10.

[0071] A penetration hole 3 a penetrating the mounting stage 3 from anupper surface thereof to a lower surface thereof is formed in themounting stage 3. To the penetration hole 3 a, a decompression pipe 4 isconnected. The decompression pipe 4 penetrates the pressurizationchamber 2, and is connected to a vacuum pump 5 present in a systemdifferent from that of a closed space formed of the pressurizationchamber 2.

[0072] The frame 6 is attached to a lower end of a freely extendablecylinder 7, and ascends and descends relative to the mounting stage 3accompanied with the extension and the contraction of the cylinder 7. Onlower end surfaces of sidewalls of the box-shaped frame 6, packings 6 aare provided. Moreover, to the lower end surface of the frame 6, asealing sheet 8 as a flexible film is adhered. The sealing sheet 8 canbe made of a highly elastic and highly strong fiber, for example, Kevlarmade by DuPont. When the frame 6 descends to the mounting stage 3, thepackings 6 a tightly contact the mounting stage 3. Hence, the peripheryof the sealing sheet 8 closely contacts the mounting stage 3 with thepackings 6 a interposed therebetween. Accordingly, a chamber as a closedspace can be formed. The chamber is connected to the vacuum pump 5, andforms the closed space together with the vacuum pump 5. In some cases,the chamber is called a decompression or first chamber 11, and thepressurization chamber 2 is called a second chamber.

[0073] Hereinbelow, description will be made for the adjusting method ofthe cell gap of the laminated body 43 c composed of the color filtersubstrate 43 a and the TFT array substrate 43 b by the use of thecell-gap adjusting apparatus 1 shown in FIG. 5 with reference to FIGS. 6to 11.

[0074] First, the laminated body 43 c is mounted on the mounting stage 3of the cell-gap adjusting apparatus 1 in a state where the frame 6ascends (S201 in FIG. 11 and FIG. 6).

[0075] After mounting the laminated body 43 c, by driving the cylinder7, the frame 6 is made to descend until the packings 6 a tightly contactthe mounting stage 3 (S202 in FIG. 11 and FIG. 7). In the process, thesealing sheet 8 is stretched while contacting the plane of the laminatedbody 43 c. In this state, an area surrounded by the mounting stage 3,the packings 6 a and the sealing sheet 8 constitutes the decompressionchamber 11 sealed from the outside. Hence, the laminated body 43 ccomposed of the color filter 43 a and the TFT array substrate 43 b isplaced in the decompression chamber (first chamber) 11 disposed in thepressurization chamber (second chamber) 2.

[0076] Next, by driving the vacuum pump 5, the decompression chamber 11is evacuated so as to be set in a decompressed state (S203 in FIG. 11and FIG. 8). Here, the cell gap of the laminated body 43 c isdecompressed through the injection port. Therefore, to the color filtersubstrate 43 a and the TFT array substrate 43 b, which constitute thelaminated body 43 c, pressures are applied in a direction of the insideof the cell gap as shown in FIG. 9. Moreover, the pressurization chamber2 is pressurized by driving the compressor 10 while maintaining thedecompressed state of the decompression chamber 11 (S204 in FIG. 11 andFIG. 8). Then, a pressure is applied to the laminated body 43 c from theoutside through the sealing sheet 8 as shown in FIG. 9. The sealingsheet 8 is a partition wall partitioning the decompression chamber 11and the pressurization chamber 2, and applies the pressure to thelaminated body 43 c. Hence, the sealing sheet 8 exerts a function as adiaphragm. Description has been made here for the example where thedecompression of the decompression chamber 11 is started, and then thepressurization of the pressurization chamber 2 is started. However, itis satisfactory if the evacuation and the pressurization aresimultaneously carried out, and an order of the starts does not matter.Hence, an order may be adopted, in which the pressurization chamber 2 isfirst pressurized, and the decompression chamber 11 is thendecompressed. Alternatively, the decompression and the pressurizationmay be simultaneously started. Furthermore, the pressure to thepressurization chamber 2 may be properly selected from a range of 0 to 9kgf/square cm, and the pressure in the decompression chamber 11 may beproperly selected from a range of 0 to 0.9 kgf/square cm.

[0077] After passage of a specified time from the start of thedecompression of the decompression chamber 11 and the pressurization ofthe pressurization chamber 2, the drives of the vacuum pump 5 and thecompressor 10 are stopped to stop the evacuation and the pressurization(S205 in FIG. 11). After stopping the evacuation and the pressurization,the frame 6 is made to ascend by driving the cylinder 7. Thereafter, thelaminated body 43 c is taken out and subjected to the heating process asa curing process for the sealant Se. Specific contents of the heatingprocess are similar to the above.

[0078] As described above, according to this embodiment, a pressure isapplied from the outside to the laminated body 43 c composed of thecolor filter 43 a and the TFT array substrate 43 b while decompressingthe cell gap. Hence, as compared with those of the conventional methodin which only decompression is performed for the cell gap, largerpressures can be applied to the color filter substrate 43 a and the TFTarray substrate 43 b. Therefore, a desired micro cell gap can be readilyobtained. Moreover, the air compressed in the cell gap does not expandafter the release of the pressure as in the conventional method in whichonly a pressure from the outside is applied to the color filtersubstrate 43 a and the TFT array substrate 43 b. Therefore, theexfoliation of the sealant Se may not be worried about. Hence, thesesubstrates are not required to be decompressed or pressurized during thecuring process for the sealant Se.

[0079] In the above-described embodiment, description has been made forthe example where the present invention is applied to the adjustingmethod of the gap width of the liquid crystal display panel 43. However,the present invention can be widely applied to articles in which gapwidths are requested to be adjusted. Moreover, the pressuring method andthe pressuring apparatus according to the present invention can beemployed not only for the adjustment of the gap width but also for otherpurposes. Particularly, the present invention is suitable for applyingpressures to a hollow article from the inside and the outside of ahollow portion thereof.

[0080] According to the present invention, there is provided a methodcapable of adjusting a micro gap width between a pair of substrates.When this adjusting method is applied to a manufacturing method of adisplay panel such as a liquid crystal display panel, a display panelwith a gap width adjusted to a specified value is obtained. Thus, theadjusting method according to the present invention contributes to theimprovement of the image quality.

[0081] Although the preferred embodiment of the present invention hasbeen described in detail, it should be understood that various changes,substitutions and alternations can be made therein without departingfrom spirit and scope of the inventions as defined by the appendedclaims.

1. A method of adjusting a gap width of a laminated body composed offirst and second substrates, comprising the steps of: obtaining saidlaminated body by laminating said first and second substrates with amember for regulating said gap width interposed therebetween; anddecompressing said gap and applying a pressure to said laminated bodyfrom the outside.
 2. The method of adjusting a gap width according toclaim 1, wherein said pressure applied from the outside is applied witha fluid taken as a pressure medium.
 3. The method of adjusting a gapwidth according to claim 1, wherein said laminated body is disposed in afirst closed space, and said gap is decompressed by allowing a suctionforce to act in said first closed space.
 4. The method of adjusting agap width according to claim 3, wherein a second closed space coveringsaid first closed space is formed, and a pressure is applied to saidlaminated body from the outside by introducing a pressurized fluid intosaid second closed space.
 5. An apparatus of adjusting a gap width of alaminated body composed of first and second substrates and having aplanar portion, comprising: a first chamber having a closed space foraccommodating said laminated body and provided with a flexible filmcontacting the planar portion of said laminated body; a second chamberhaving a closed space for accommodating said first chamber; adecompressor for applying a decompression force to said first chamber;and a pressurizer for applying a pressurization force to said secondchamber.
 6. The apparatus of adjusting a gap width according to claim 5,wherein said first chamber comprises: a mounting stage for mounting saidlaminated body; and said flexible film forming said closed space withsaid mounting stage by closely contacting a periphery thereof to saidmounting stage, and said laminated body is accommodated in said closedspace.
 7. The apparatus of adjusting a gap width according to claim 6,wherein said pressurizer applies a pressurization force to said secondchamber by introducing a pressurized fluid thereto, and thepressurization force is allowed to act on said laminated body throughsaid flexible film.
 8. The apparatus of adjusting a gap width accordingto claim 5, wherein the pressurization force is applied to said secondchamber by said pressurizer while the decompression force is applied tosaid first chamber by said decompressor.
 9. A manufacturing method of adisplay panel in which a display medium is sealed between a pair ofsubstrates disposed opposite to each other, said substrates beingseparated from each other with a gap of a specified width, said methodcomprising the steps of: (a) coating sealant in the form of a pictureframe on a peripheral portion of at least one of said pair of substratesexcept an injection port for said display medium; (b) obtaining alaminated body having the gap of the specified width by laminating saidpair of substrates with said sealant interposed therebetween; (c)applying a pressure to said pair of substrates from the outside whiledecompressing said gap; (d) curing said sealant; and (e) injecting saiddisplay medium from said injection port after curing said sealant. 10.The manufacturing method of a display panel according to claim 9,wherein in said step (c), the pressure applied from the outside isapplied with a fluid taken as a pressure medium.
 11. The manufacturingmethod of a display panel according to claim 9, wherein in said steps(c) and (d), a curing process for said sealant is carried out after saiddecompressing process and said pressure applying process.
 12. Themanufacturing method of a display panel according to claim 9, wherein insaid step (c), the pressure in said gap is equal to the atmosphericpressure or lower.
 13. A method of applying a pressure to an articlewith a hollow portion communicating with the outside, said methodcomprising the steps of: applying a pressurization force to said articleby a fluid in a state where said article is disposed in a closed space;applying a decompression force to said hollow portion through a systemdifferent from that of said closed space, said hollow portioncommunicating with said system.
 14. An apparatus of applying a pressureto an article, comprising: a first chamber having a closed space foraccommodating said article and provided with a diaphragm in a partthereof; a second chamber provided with a closed space including saidfirst chamber; a decompressor for applying a decompression force to saidfirst chamber; and a pressurizer for applying a fluid pressure to saidsecond chamber, wherein said diaphragm applies a pressure to saidarticle when said decompressor applies the decompression force to saidfirst chamber, and applies the pressure to said article when saidpressurizer applies the fluid pressure to said second chamber.